Download 01 Historical stages of Therapeutic Dentistry, its chapters

Ternopil State Medical University
named by I. Horbachevskyj
Topic.
Historical stages of
Therapeutic Dentistry, its chapters.
The value of scientific research of
Ukrainian
scientists.
Dental
instruments.
Histological
and
clinical anatomy of the teeth. Dental
charting. Signs of teeth.
Department of Therapeutic Dentistry
Lecturer: Levkiv Mariana
1
Dentistry, is the branch of medicine that is
involved in the evaluation, diagnosis, prevention,
and surgical or non-surgical treatment of
diseases, disorders and conditions of the oral
cavity, maxillofacial area and the adjacent
associated structures and their impact on the
human body.
2
•
Therapeutic Dentistry includes such chapters:
Propaedeutic
course;
Preventive dentistry
and
Endodontology;
Periodontology;
Oral Pathology(deals with oral
mucosa
diseases)
3
BASIC INSTRUMENTS
• There are a few basic instruments that are
universal to almost every procedure in
dentistry.
4
Hand
instruments
Working end(s) of instruments
•Are the functional parts of the instrument
• Can have a variety of functions including: cutting,
packing, carving, placing and condensing
•Are adapted to the function of the particular instrument
•May be bevelled (i.e. the working end is cut at an angle)
• An instrument can be single-ended (one working end)
or double-ended (two working ends)
Shank of an instrument
• The part between the working end and the handle
• Can be straight or angled
• The function of the instrument determines the angle
and flexibility of the shank
Handle of an instrument
• Is the part of the instrument that the operator grasps
• Design is related to the function of the instrument
5
Set of examination instruments
Mouth mirror
Functions
• •To provide indirect vision
• •To reflect light
• • For retraction and protection of oral tissues
• • For magnification (the number of the mirror
represents size of mirror head)
6
Sickle/contra-angled probe
Functions
• • Detection of:
•
defective pits and fissures;
•
calculus;
•
deficient margins of restorations, crowns and bridges;
•
caries;
• • Examination (pointed tip allows good tactile sensitivity)
Varieties
• • Can be single-ended or double-ended
• • Many different styles available
• •Working ends may vary (straight, curved)
7
Periodontal probe
Function and features
• Measure the depth of periodontal pockets
•Tip is calibrated in millimetres
•Blunt end reduces the possibility of tissue trauma
Varieties
• Single-ended or double-ended
• Can be straight, curved or at right angles
• Plastic types available
8
College tweezers
Functions
• • Placing small objects in the mouth and retrieving small
objects from the mouth
• • Locking type ‘lock’ to prevent dropping materials
Varieties
• • Locking and non-locking types
• •Working ends can be straight, curved, serrated or smooth
9
INSTRUMENTS USED IN
BASIC RESTORATIVE
PROCEDURES
Spoon excavators
Functions and feature
• •A spoon-shaped working end for ‘spooning’ out dentinal
caries from the cavity preparation
• • Edges of working end are sharp
• Any remaining caries will be removed with the conventional
handpiece and a round bur
10
Mixing spatulas
Function and feature
• • Used to mix dental materials
• • Anodised aluminium spatula will not stick to any composite
materials or discolour materials
11
Flat plastic instrument.
Also called: plastic instrument
Functions
• •To deliver materials to the cavity preparation
• •To remove excess materials
Varieties
• •Various sizes and shapes available
• • Can be single-ended or double-ended
12
Round-ended plastic
Functions and feature
• •Used to create anatomical shapes in composite material
during restorations
• •The ball-ended plastic instrument can also be used to pack
and condense composite materials
13
Rotary instruments
HANDPIECES AND BURS
• Dental handpieces and rotary attachments
help to make dental treatment more
comfortable for the patient and reduce the
amount of time needed to complete
procedures.
14
Air turbine handpiece
Also called: fast handpiece, high speed handpiece, air rotor handpiece
Type
• Contra-angled
Functions, precaution and features
• • Removal of tooth tissue during restorations and preparation of
teeth for fixed prosthetic appliances
• • Polishing of restorations
• • High speeds create heat and friction – handpiece must be run with
water to cool the tooth to prevent pulpal damage
• • High speed saves treatment time and reduces vibration
15
Driven by
•Turbine – may need to be lubricated – check manufacturer’s instructions
• Compressed air rotates the turbine, which then rotates the bur
Speed
Check manufacturer’s specifications (can run up to 500000rpm)
Grip
Accepts friction grip attachments
Attachment
Dental unit
Varieties
• Different types of chucks available (e.g. those which need bur changing
tool)
•With or without light
• Smaller heads for difficult access
16
Straight handpiece
Functions
• • Used in surgical procedures to remove bone (cannot use air
turbine as the water is not sterile)
• • Used extra-orally at chairside or in the dental laboratory (e.g. for
denture adjustments)
Speed
• can run up to 40 000rpm
Grip
• Accepts long shank attachments
Attachment
• Electric motor that fits into the base of the handpiece
17
Slow Speed Handpieces
Type
• Contra-angled
Functions
• • Removal of caries
• • Polishing
• •Procedures that require torque
• •Refine cavity preparations and adjust occlusion
Driven by
• Gears
Speed
• The speed of the handpiece ranges from 0 to 40 000 rpm
Attachment
• Electric motor that fits into the base of the handpiece
18
Burs
Head
• This is the working end
• Function depends on the size and shape of the head
• Many different sizes and shapes, each used for a different
function (cutting, polishing and finishing)
Neck
• The part that connects the head to the shank – usually narrows
towards the head
Shank
• The part that fits into the handpiece
• Shapes and lengths vary, depending
on function
• Can sometimes be marked to identify bur type (stripes or coloured bands)
19
Some points to remember about rotary
attachments and burs
• Most often called burs, but also available are wheels, discs,
rubber points, rubber cups and stones
• Each has a particular function (cutting, polishing, finishing or
caries removal)
•Are made from various materials (tungsten carbide, diamond
and steel)
• Can have flutes (the cutting edges)
•The end of the shank determines which handpiece the
attachment will fit into:
 Long straight shank – straight handpiece
 Latch grip – conventional type/slow speed handpiece
 Friction grip shank – air turbine handpiece/high speed
handpiece
 Other various attachments such as snap or screw-type
attachments
20
Shape and function
•
•
•
•
Shape determines function; the examples that follow relate
to tungsten carbide burs:
• Rose head/round – cutting and removing caries
• Pear – to shape the cavity preparation
• Fissure – to shape and prepare the cavity preparation
21
Grip and corresponding handpiece
Refers to the way the bur’s shank is ‘gripped’ into the
handpiece
• Composition
• •Refers to the head of the bur and what it is made from
• • Generally:
•
Most latch grip burs are made of steel
•
Most fiction grip burs are made of tungsten carbide or
diamond
•
Most long shank burs are made from steel if they are meant
for surgical procedures and stainless steel if they are meant
for laboratory purposes
22
Anatomical and histological features of
teeth
1.
In adult humans there are 32 permanent teeth.
2.
These are preceded during
childhood by 20 deciduous teeth.
3.
The tooth lies in a bony socket,
the alveolus, that is covered an oral
mucosa called the gingiva (gums)
Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.
23
Tooth structure
24
Enamel
• Structure of enamel
• Enamel is made up of millions of enamel prisms or
rods, which run from the amelo-dentinal junction to the
enamel surface. Each prism is made up of a large
number of enamel crystallites.
25
Dentine
•
•
Structure of dentine
Dentine consists of many dentinal tubules that run parallel to each other,
following a double curved course, and extend from the pulp to the amelodentinal junction. Each dentinal tubule contains an odontoblast process
surrounded by intercellular ground substance composed of fine collagenous
fibrils. The odontoblast cells are a layer of closely arranged cells on the
pulpal surface of the dentine with their nuclei situated at the basal (pulpal)
end of each cell.
26
Cementum
•
•
•
•
Physical characteristics of cementum
Cementum is a pale yellow, calcified tissue covering the root dentine. It is
softer than dentine and can easily be worn away, resulting in exposure of
the dentine. Its thickness varies according to location; it is thickest towards
the apical third of the root and thinnest cervically.
Chemical composition of cementum
Cementum is 65% by weight inorganic (mainly hydroxy-apatite), 23%
organic (mainly collagen) and 12% water.
27
Dental pulp
•
The dental pulp is surrounded by dentine and is contained in
a rigid compartment.
•
•
•
Functions of pulp
The dental pulp has the following functions:
■ At late bell stage the cells at the periphery of the pulp
differentiate into odontoblasts forming dentine.
• ■ It provides nutrients to the odontoblasts. (trophic function )
• ■ It acts as a sensory organ especially when dentine is
exposed. The pulp rapidly responds to stimuli such as caries
and attrition by laying down reparative or reactionary
dentine. (reparative function)
• ■ It mobilises defence cells when bacteria enter it.
(protective function)
• ■ Cells proliferating in the pulpal tissue create pressure; this
is thought to play a part in tooth eruption.
28
Periodontal ligament
29
TEETH STRUCTURE
Primary
teeth
30
TEETH STRUCTURE
Permanent
teeth
31
TOOTH FUNCTION
Types
Function
1. Incisor
Incisor is a tooth that has one root;
function: to cut and cut off food.
2. Canine
Canines are the teeth that have one
root and has the function to rip the food.
3. Premolar
teeth that had two/one roots; used to
grind and chew food.
4. Molar
Molar tooth is a tooth that has two/three
roots; have a function for crushing and
chewing food.
Morphological differences between primary
and permanent teeth
•
•
•
•
•
•
•
•
•
•
There are numerous differences between the primary and permanent dentition,
many of which give rise to considerations in relation to operative treatment.
Essentially, primary teeth have:
■ A shorter crown.
■ A lighter colour.
■ Narrower occlusal surfaces.
■ Thinner enamel and dentine.
■ Relatively larger pulps.
■ Curved roots
(to accommodate the
developing permanent
successor).
Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.
33
Numbering Systems
• Universal/National System
– Developed in 1968
– Most commonly used in the United States
• Fédération Dentaire Internationale System
– Canada and European countries use this
– Easily adapted by computer and is widely
used in most countries
• Palmer System
34
Universal numbering system
A system is used in the United States, called the universal system. This is a
two-digit system but the teeth are numbered from 1 through to 32 in a
clockwise direction starting with the upper right third molar:
Right 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Upper
Lower 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 Left
35
ISO/FDI numbering system
The mouth is divided into four quadrants and each quadrant is given a
number, starting with the upper right quadrant and working in a clockwise
direction.
For example, the upper left quadrant is 2. The teeth are then allocated a
number starting from the midline, so all central incisors are 1 and all third
molars are 8. Therefore the lower right second premolar is 45.
Right 18 17 16 15 14 13 12 11 21 22 23 24 25 26 27 28 Upper
Lower 48 47 46 45 44 43 42 41 31 32 33 34 35 36 37 38 Left
36
Palmer Notation System
In this system, the dentition is divided into quadrants and the teeth in each
quadrant are numbered 1 to 8 starting at the midline. Each quadrant is
separated by a vertical line for right and left and by a horizontal line for
upper and lower. Thus |6 is the upper left first molar in the permanent
dentition. Right 8 7 6 5 4 3 2 1 | 1 2 3 4 5 6 7 8 Upper
Lower 8 7 6 5 4 3 2 1 | 1 2 3 4 5 6 7 8 Left
37
Universal/National Numbering
and Lettering System
8 9
Maxillary
right
Maxillary
left
E
F
Maxillary
right
1
16
A
17
T
Third molars
32
Mandibular
right
Mandibular
right
Mandibular
left
Maxillary
left
J
Second molars
P
O
K
Mandibular
left
Primary teeth
25 24
Permanent teeth
38
Fédération Dentaire Internationale
System for Numbering
1
Maxillary right
quadrant “1”
1
Maxillary left
quadrant “2”
1
1
Maxillary right
quadrant “5”
8
Third molars
8
8
5
8
5
Mandibular right
quadrant “8”
Mandibular right
quadrant “4”
1
1
Mandibular left
quadrant “3”
Maxillary left
quadrant “6”
5
Second molars
1
1
5
Mandibular left
quadrant “7”
Primary teeth
Permanent teeth
39
Palmer System for Numbering
1
1
Maxillary
right
quadrant
Maxillary
left
quadrant
Maxillary
right
quadrant
A A
Maxillary
left
quadrant
8
8
E
E
8
8
E
E
Mandibular
right
quadrant
Mandibular
left
quadrant
1
Mandibular
right
quadrant
A A
Mandibular
left
quadrant
Primary teeth
1
Permanent teeth
40
Overview: Ergonomics and Health
Implications for Dental Hygienists
• Increase awareness
•
•
•
•
•
•
Decrease work-related pain and injuries
Heighten productivity
Improve musculoskeletal health
Increase comfort
Improve quality of life
Extend careers
What is Ergonomics?
• Ergonomics is the study of
workers and their relationship
with their occupational
environment
• How you position yourself,
your patient, how equipment
is utilized, how the workplace
is designed and how it
impacts your health
• ERGONOMICS is a way to
work smarter, more efficiently
with less effort and
discomfort to the human body
Ergonomics in the Dental Health Field
• Studies show work-related
pain in the dental field is not
decreasing
• Over half of all dental
professionals continue to
experience work-related
pain
• Why? The physically
challenging nature of the
work with numerous risk
factors
Risk Factors
• Prolonged Static Postures
• Repetitive Movements
• Working in a confined
space
• Challenges with
positioning yourself or
the patient
• Limitations with the tools
and equipment used
©2008, Valachi from “Practice Dentistry Pain-Free”
Consequences of Poor Ergonomics
•
•
•
•
Fatigue
Pain/Discomfort
Illness/Injury
Missed days at
work
• Errors
• Lower productivity
• Patient
dissatisfaction
Poor Ergonomics: Signs and Symptoms
Physical Signs
Symptoms
• Decreased range of
motion
• Pain
• Deformity
• Tingling
• Decreased grip
strength
• Burning
• Loss of muscle
function
• Stiffness
• Numbness
• Cramping
©2008, Valachi from “Practice Dentistry Pain-Free”
Poor Ergonomics = Musculoskeletal
Disorders
The World Health Organization definition:
Musculoskeletal Disorder is “a disorder of the muscles,
tendons, peripheral nerves or vascular system not directly
resulting from an acute trauma or instantaneous event”
Two Most Common Causes for Musculoskeletal
Disorders in the Dental Health Profession
Cumulative Traumas
Prolonged Static Postures
©2008, Valachi from “Practice Dentistry Pain-Free”
Cumulative Trauma
• Repetitive Movements like
Scaling and Polishing are
Cumulative Traumas
• Vibrations transmitted by
dental handpieces or
mechanical scalers are
Cumulative Traumas
• Cumulative Traumas add
up
These microtraumas cause
“wear and tear” on the
muscles, tendons, and
nerve tissue
Prolonged Static
Postures
• Human body was designed for
movement
• Dental hygiene procedures
means practitioners must
maintain static postures
• Hygienists hold postures that
require more than 50% of the
body’s muscles to contract to
resist gravity
• Muscle overload leads to
decreased blood flow and
increased pressure on the
muscles and joints
©2008, Valachi from “Practice Dentistry Pain-Free”